Most conventional personal computers utilize a hard disk drive (or "HDD") as the principal means for storing frequently used software and data. A wide variety of hard disk drives are available and well known in the art. For example, hard disk drives may be internal (i.e. mounted within the computer) or external (i.e. separately packaged and connected to the computer). Many hard disk drives are also removable or detachable, allowing the disk drives (and the information stored thereon) to be exchanged between different computers or stored in secure locations when not in use.
Where a HDD is removable, it is essential that the HDD be removed and installed properly. If removal or installation of a HDD is not handled properly, a variety of problems can result. For example, if the HDD is removed or installed while the power to the computer system is on, then electrical damage may occur to the HDD and/or the computer system. If the HDD is removed while data on the HDD is being accessed, the data may be missed or permanently lost. If the HDD is changed and the computer system is not reset (or "booted") to account for the installation and the parameters of the new HDD, then serious data errors will occur. Any data that is read will be incorrect, and any data that is written will be lost. Additionally, data on the HDD will be destroyed. If the new HDD has a different operating system or environment from the previous HDD, the system can "freeze," and must thereafter be rebooted.
To avoid these problems, certain procedures ordinarily must be followed whenever a HDD is removed or replaced. The computer system should be turned off before a HDD is removed or installed. Before turning off the system, users should save any new data, and should also wait for the HDD access to be completed.
Currently, users are assumed to be familiar with these requirements for HDD removal and replacement. Relying on the user's knowledge of these procedures is undesirable, however, in that it does not account for human error. Additionally, inexperienced or infrequent users may not be familiar with HDD removal/replacement procedures.
The possibility of user error increases when the computer has one or more energy conservation modes (variously referred to by such names as "sleep", "resume", "suspend" or "standby" modes), which are used to conserve battery power when the computer is not in use. Various types of energy conservation modes are currently used. In some computer systems, when the computer is placed in an energy conservation mode, certain components (such as the display and/or the HDD) are turned off, but power is still supplied to the main random access memory ("RAM"). In such systems, data is preserved and ready to use immediately when the system is again placed in use (i.e. the system provides an "instant on" function). In other types of systems, when the computer system is placed in an energy conservation mode, the state of the system (i.e. contents of memory and various types of registers) immediately is stored in a nonvolatile memory, allowing power to be cut off from the RAM or the entirety of the system. In such systems, data must be returned to the RAM when the system is again turned on, imposing some delay prior to use. In either case, when normal operation resumes, the state immediately prior to placing the computer in energy conservation mode is restored, and the system does not reboot (i.e. reset, taking into account the parameters of various components of the system). This allows the user to continue working exactly where he or she left off. It also allows the user to begin work relatively quickly, rather than waiting for the system to perform a lengthy boot procedure.
When a computer system is in an energy conservation mode that does not involve turning off power to the entire system, the system is sometimes referred to as being suspended. When a system is suspended, it often appears to be turned off because the display is turned off. For this reason, users may erroneously assume that it is safe to change the HDD. In some types of energy conservation modes (sometimes referred to as "standby" modes), the HDD actually remains on, and removal of the HDD can result in data loss and/or electrical damage as described above. Even if the HDD is off, however, the computer will not reboot when normal operation resumes from a conventional energy conservation mode. Thus, the computer will not be aware that the HDD has been replaced and data errors will occur as described above.
Accordingly, there is a need for a computer system that allows for safe removal and replacement of HDDs even when the computer is on or in an energy conservation mode.